The present invention relates generally to releasably connecting a vehicle enclosure to a frame of the vehicle. In particular, the present invention relates to a hood and fender assembly mounting system for connecting a forwardly tiltable hood and fender assembly of a heavy duty truck to a frame of the vehicle and assisting in the opening and closing of the hood and fender assembly.
Conventional heavy duty trucks typically have a hood and fender assembly and a cab which are both supported by a frame of the truck. The hood and fender assembly is often made from a fiberglass reinforced composite material and is hinged to the frame at a forward end of the assembly. The cab is typically a metal weldment or riveted assembly mounted on the frame. The hood and fender assembly may be pivotably mounted and biased by a counter balancing spring which biases the hood and fender assembly toward either the open or closed position thereby easing operation of the hood and fender assembly when access to the engine is needed. The hood and fender assembly may also include a spring or damper device which controls the rate of travel of the hood and fender assembly in one or both directions, preventing sudden movement during operation of the hood and fender assembly. When the hood and fender assembly is in a closed position, the rearward end of the hood and fender assembly is generally mounted on and fastened to the cab.
Typically, spring loaded latches or elastic straps releasably connect a closed hood and fender assembly to, and in engagement with, the cab. The latch or strap is typically accessible only from outside of the vehicle. This generally requires a vehicle driver or mechanic to be outside the vehicle and access a first latch on one side of the hood and fender and then move to the other side of the vehicle and access a second latch on the other side of the vehicle.
This known latch or strap arrangement has disadvantages. One disadvantage is the amount of movement around both sides of the exterior of the truck on the part of the driver or mechanic to release or connect the latches. Another disadvantage is a lack of security. Any unauthorized person may access the engine and engine compartment merely by releasing the latches and pivoting the hood and fender assembly.
Frequently the mounting of the cab of an over-the-highway vehicle on a frame includes a shock absorbing mechanism. The shock absorbing mechanism allows a limited amount of movement of the cab relative to the frame while absorbing vibration and road shocks to improve ride qualities for an operator and any passengers. As the vehicle is operated, the respective movements of the hood and fender assembly and the cab relative to the frame and any torsional twisting of the frame which may occur during use cause considerable relative movement between the hood and fender assembly and the cab. This interaction between the hood and fender assembly reduces the ride quality by limiting the motion of the cab on its shock absorber and causing additional forces on the cab which degrade ride quality. Since the hood and fender assembly and the cab are typically relatively tightly engaged, relative movement causes undesirable forces to act between the hood and fender assembly and the cab. A large gasket between the hood and fender assembly and the cab may be needed to cushion these forces. Since the hood and fender assembly is typically a composite material while a cab is metal, these forces may disfigure the hood and fender assembly creating an undesirable and unsightly condition.
Typical counter balancing springs may be torsion bars which have a circular cross section. While a circular configuration allows for adjustment of the amount of bias on the hood and fender assembly, it may also require the use of additional fixing methods or connecting devices to secure the ends of the torsion bar.
The present invention provides a new and improved body panel support and latch system which is especially adapted for over-the-highway heavy duty type tractor vehicles. The invention includes a frame structure which includes a portion that supports an operator cab and a portion for mounting a prime mover or engine, forward of the cab. A body panel which, in the illustrated embodiment, comprises a hood and fender assembly is movable between opened and closed positions and is operative to enclose an engine compartment when in the closed position. At least one hood latch mechanism maintains closure of the hood and fender assembly and includes first and second latching assemblies.
The first latching assembly is attached directly to the frame preferably by a strut which is attached to and extends laterally from the frame structure and the second latching assembly is attached to a rear section of the hood and fender assembly. The first and second latching assemblies are engagable when the hood and fender assembly is moved to its closed position.
In the preferred and illustrated embodiment, at least one pivot assembly is mounted to a forward end of the frame structure and mounts a forward end of the hood and fender assembly for pivotal movement. With the disclosed mounting system, the hood and fender assembly is entirely supported by the frame structure, independent of the operator cab.
In the more preferred embodiment, the forward end of the hood and fender assembly is pivotally attached to the frame by two hinge assemblies. Each hinge assembly preferably includes a J-bracket, a portion of which is bolted to the hood assembly. A spring assist provided by at least one torsion bar aids in the opening and closing of the hood and fender assembly.
In the exemplary embodiment, two torsion bars are provided, each having a hex-shaped cross-section. Each J-bracket includes a hex-shaped socket adapted to receive one end of a torsion bar. The socket is located on the pivot axis of the hinge assembly so that as the hood and fender assembly opens or closes the end of the torsion bar received in the socket is rotated. The socket is enclosed in a rubber ring isolator to cushion the frontward portion of the hood and fender assembly from the frame. The opposite end of the torsion bar is received in a stationary hex-shaped opening where it is held against rotation. Thus, as the hood and fender assembly is closed, each torsion bar is twisted thus, generating a preload which aids in opening and closing of the hood and fender assembly. The hex-shaped torsion bar allows for adjustment while easing assembly by eliminating the need for additional connecting devices or fixing methods which may be necessary with torsion bars of circular cross section. The present invention further provides alignment structure which allows for adjustment of the preload of the torsion bars prior to the installation of the hood and fender assembly to the frame.
According to a feature of the invention, at least one motion control device is provided which controls the rate of travel of the hood and fender assembly as it moves between the opened and closed positions. In the preferred and illustrated embodiment, the motion control device comprises a fluid filled, extendable cylinder one end of which is attached to the hood and fender assembly, the other end of which is coupled to the frame structure. The combination of the torsion bar and a damper control regulates the effort required to move the hood and fender assembly and also limits the rate of- travel of the hood and fender assembly, providing for predictable-operation of the hood and fender assembly.
The latch system automatically connects itself upon pivotal movement of a hood and fender assembly to a fully closed position to interconnect the hood and fender assembly to the frame. The latch system includes a handle located within a cab of a truck which is actuatable to release the connection. Thus, the driver or mechanic does not have to be located outside the cab and move to both sides of the truck to release or connect the latch system. If doors of the cab are locked with the latch system connected, unauthorized access to the engine compartment is inhibited. Since the hood and fender assembly is releasably connected to the frame rather than the cab, forces caused by relative assembly and cab movements can be and are reduced and resultant disfiguring damage to the hood and fender assembly and degradation of ride quality are avoided.
The apparatus includes a first latching assembly attached to the frame. A coacting latching assembly is attached to the hood and fender assembly at a distal location relative to the hinge. The latching assemblies are releasably interconnected when the hood and fender assembly is in a position which encloses the engine to locate and to maintain the hood and fender assembly in a predetermined position relative to the frame independent of the cab. The releasable latching assembly has a lock lever which is movable between a latched position engaging the coacting latching assembly and an unlatched position for disengagement from the coacting latching assembly. A movable handle is located within the cab. A cable connects the handle with the lock lever to move the lock lever from the latched position to the unlatched position in response to movement of the handle.
The coacting latching assembly includes a shaft attached at a mounting end portion to the hood and fender assembly. A guide member is movable along the shaft. A bias mechanism urges the guide member away from the mounting end and toward an outer end of the shaft. The releasable latching assembly includes a cup shaped receiver having an opening extending therethrough. A surface on the guide member engages the cup shaped receiver when the hood and fender assembly pivots to a substantially closed position to move the guide member towards the mounting end of the shaft against a force of the bias mechanism. The outer end of the shaft is exposed during movement of the hood and fender assembly from the partially closed position to a fully closed position and extends through the opening in the receiver. The lock lever engages the shaft near an end portion from the opening to prevent movement of the hood and fender assembly towards an open position. The lock lever includes a slot which acts on a rivet to limit travel of the lock lever to an acceptable range.
The coacting latching assembly includes a shoulder near the outer end of the shaft to engage a portion of the lock lever and maintain the receiver and the guide member engaged with the latching assembly in the fully closed position. Surfaces of the cup-shaped receiver on the guide member are frusto-conical to guidingly align the latching assembly during latching movement. The outer end of the shaft cams the lock lever in a direction transversely away from the shaft as it is moved to a position extending from the opening in the receiver.
Accordingly, an object of the invention is to provide a heavy duty over-the-highway vehicle with a novel and improved hood and fender assembly mounting system.